$OpenBSD: patch-wmnet_c,v 1.4 2013/11/22 15:35:22 sthen Exp $
--- wmnet.c.orig	Fri May  5 02:01:14 2000
+++ wmnet.c	Fri Nov 22 15:32:16 2013
@@ -49,34 +49,51 @@
  *  5/4/2000   --  Support added for OpenBSD
  */ 
 
-#include<stdlib.h>
-#include<stdio.h>
-#include<X11/X.h>
-#include<X11/Xlib.h>
-#include<X11/Xutil.h>
-#include<X11/Xatom.h>
-#if defined (__FreeBSD__) || defined (__OpenBSD__)
-# include<sys/socket.h>
-# include"getopt.h"
-#else
-# include<getopt.h>
-#endif
-#include<net/if.h>
-#include<signal.h>
-#include<unistd.h>
-#include<string.h>
-#include<math.h>
-#include<sys/time.h>
-#include<sys/socket.h>
-#include<sys/types.h>
-#include<sys/ioctl.h>
-#include<sys/wait.h>
-#include<X11/extensions/shape.h>
+#include <sys/types.h>
+#include <sys/ioctl.h>
+#include <sys/socket.h>
+#include <sys/time.h>
+#include <sys/wait.h>
 
+#include <net/if.h>
+
+#include <X11/extensions/shape.h>
+#include <X11/X.h>
+#include <X11/Xatom.h>
+#include <X11/Xlib.h>
+#include <X11/Xutil.h>
+
+#include <err.h>
+#include <getopt.h>
+#include <math.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
 #include "XPM/arrow.xbm"
 #include "wmnet.h"
 
+/* X Stuff */
+static Display *dpy;
+static Window root_window, main_window, icon_window, *visible_window;
+static Pixmap arrow;
+static Atom delete_atom;
+static int screen, specified_state = -1;
+static GC graphics_context;
+static unsigned long tx_pixel[3], rx_pixel[3], labelfg_pixel, labelbg_pixel,  black_pixel, white_pixel, darkgrey_pixel, grey_pixel;
 
+static char *click_command = NULL, *label = NULL;
+static struct timeval timenow, timelast;
+static unsigned int delayTime = 25000, displayDelay = 55000, maxRate = 6000;
+static unsigned int graphbox_height = 44;  /* number of rule in /proc/net/ip_acct to use */
+static Bool logscale = False;
+
+parser_func stat_gather;
+
+static struct if_data_t id;
+
 /* Called on exit() from atexit() */
 void exit_func(void) {
 	XCloseDisplay(dpy);
@@ -90,8 +107,6 @@ void got_signal(int x) {
 	} else exit(7);
 }
 
-
-
 /* Does generic setting up of wmnet, (option parsing) and calls setupX() */
 void setup_wmnet(int argc, char **argv) {
 	int c;
@@ -143,10 +158,14 @@ void setup_wmnet(int argc, char **argv) {
 				exit(14);
 				break;
 			case 'W':
-				device = strdup(optarg);
+				id.device = strdup(optarg);
+				if (id.device == NULL)
+					err(1, "memory allocation for device");
 				break;
 			case 'D':
 				parser = strdup(optarg);
+				if (parser == NULL)
+					err(1, "memory allocation for parser");
 				break;
 #ifdef linux
 			case 'T':
@@ -162,9 +181,10 @@ void setup_wmnet(int argc, char **argv) {
 				graphbox_height = 35;	
 				if (label == NULL) {
 					label = strdup(optarg);
+					if (label == NULL)
+						err(22, "memory allocation for label");
 				} else {
-					fprintf(stderr, "wmnet: duplicate --label\n");
-					exit(22);
+					errx(22, "duplicate --label");
 				}
 				break;
 			case 'B':
@@ -172,8 +192,7 @@ void setup_wmnet(int argc, char **argv) {
 					labelbgcolorString = (char *)alloca(strlen(optarg)+1);
 					strncpy(labelbgcolorString, optarg, strlen(optarg)+1);
 				} else {
-					fprintf(stderr, "wmnet: duplicate --labelbg\n");
-					exit(23);
+					errx(23, "duplicate --labelbg");
 				}
 				break;
 			case 'F':
@@ -181,8 +200,7 @@ void setup_wmnet(int argc, char **argv) {
 					labelfgcolorString = (char *)alloca(strlen(optarg)+1);
 					strncpy(labelfgcolorString, optarg, strlen(optarg)+1);
 				} else {
-					fprintf(stderr, "wmnet: duplicate --labelfg\n");
-					exit(23);
+					errx(23, "duplicate --labelfg");
 				}
 				break;
 			case 'l':
@@ -193,8 +211,7 @@ void setup_wmnet(int argc, char **argv) {
 					rxcolorString = (char *)alloca(strlen(optarg)+1);
 					strncpy(rxcolorString, optarg, strlen(optarg)+1);
 				} else {
-					fprintf(stderr, "wmnet: duplicate --rxcolor\n");
-					exit(18);
+					errx(18, "duplicate --rxcolor");
 				}
 				break;
 			case 't':
@@ -202,8 +219,7 @@ void setup_wmnet(int argc, char **argv) {
 					txcolorString = (char *)alloca(strlen(optarg)+1);
 					strncpy(txcolorString, optarg, strlen(optarg)+1);
 				} else {
-					fprintf(stderr, "wmnet: duplicate --rxcolor\n");
-					exit(19);
+					errx(19, "duplicate --txcolor");
 				}
 				break;
 			case 'x':
@@ -217,9 +233,10 @@ void setup_wmnet(int argc, char **argv) {
 			case 'e':
 				if (click_command == NULL) {
 					click_command = strdup(optarg);	
+					if (click_command == NULL)
+						err(17, "memory allocation for click command");
 				} else {
-					fprintf(stderr, "wmnet: duplicate --execute\n");
-					exit(17);
+					errx(17, "duplicate --execute");
 				}
 				break;
 			case 'w':
@@ -234,19 +251,16 @@ void setup_wmnet(int argc, char **argv) {
 					struct ifreq ifr;
 					strncpy(ifr.ifr_name, optarg, IFNAMSIZ );
 					ifr.ifr_name[IFNAMSIZ-1] = 0;
-					if ((fds = socket(AF_INET, SOCK_DGRAM, 0)) == -1 || ioctl(fds, SIOCGIFFLAGS, &ifr) == -1 ) {
-						perror("wmnet");
-						exit(20);
-					}
+					if ((fds = socket(AF_INET, SOCK_DGRAM, 0)) == -1)
+						err(20, "socket()");
+					if (ioctl(fds, SIOCGIFFLAGS, &ifr) == -1 )
+						err(20, "SIOCGIFFLAGS");
 					if ((ifr.ifr_flags & IFF_PROMISC) != 0) {  /* Is promiscuous mode not already unset? */
 						ifr.ifr_flags &= ~IFF_PROMISC;
-						if (geteuid() != 0) {
-							fprintf(stderr, "wmnet: this must be suid or you must be root!\n");
-						}
-						if(ioctl(fds, SIOCSIFFLAGS, &ifr) != 0) {
-							fprintf(stderr, "wmnet: cannot unset promiscuous mode on %s\n", optarg);
-							exit(21);
-						}
+						if (geteuid() != 0)
+							warnx("this must be suid or you must be root!");
+						if(ioctl(fds, SIOCSIFFLAGS, &ifr) != 0)
+							err(21, "cannot unset promiscuous mode on %s", optarg);
 					}
 					close(fds);
 				}
@@ -257,19 +271,16 @@ void setup_wmnet(int argc, char **argv) {
 					struct ifreq ifr;
 					strncpy(ifr.ifr_name, optarg, IFNAMSIZ );
 					ifr.ifr_name[IFNAMSIZ-1] = 0;
-					if ((fds = socket(AF_INET, SOCK_DGRAM, 0)) == -1 || ioctl(fds, SIOCGIFFLAGS, &ifr) == -1 ) {
-						perror("wmnet");
-						exit(16);
-					}
+					if ((fds = socket(AF_INET, SOCK_DGRAM, 0)) == -1)
+						err(16, "socket()");
+					if (ioctl(fds, SIOCGIFFLAGS, &ifr) == -1 )
+						err(16, "SIOCGIFFLAGS");
 					if ((ifr.ifr_flags & IFF_PROMISC) == 0) {  /* Is promiscuous mode not already set? */
 						ifr.ifr_flags |= IFF_PROMISC;
-						if (geteuid() != 0) {
-							fprintf(stderr, "wmnet: this must be suid or you must be root!\n");
-						}
-						if(ioctl(fds, SIOCSIFFLAGS, &ifr) != 0) {
-							fprintf(stderr, "wmnet: cannot set promiscuous mode on %s\n", optarg);
-							exit(13);
-						}
+						if (geteuid() != 0)
+							warnx("wmnet: this must be suid or you must be root!");
+						if(ioctl(fds, SIOCSIFFLAGS, &ifr) != 0)
+							err(13, "cannot set promiscuous mode on %s", optarg);
 					}
 					close(fds);
 				}
@@ -313,31 +324,24 @@ void setup_wmnet(int argc, char **argv) {
 	/* Relinquish suid privileges if there */
 	seteuid(getuid());
 
-	stat_gather = setup_driver(parser);
+	stat_gather = (parser_func)setup_driver(parser, &id);
 
-
 	if (txcolorString == NULL) txcolorString = "white";
 	if (rxcolorString == NULL) rxcolorString = "red";
 	if (labelfgcolorString == NULL) labelfgcolorString = "white";
 	if (labelbgcolorString == NULL) labelbgcolorString = "black";
 
 	/* Change dir to /, security precaution, and common courtesy */
-	if (chdir("/") == -1) {
-		perror("wmnet: chdir()");
-		exit(16);
-	}
+	if (chdir("/") == -1)
+		err(16, "chdir()");
 
 	/* Open X Display */
-	if ((dpy = XOpenDisplay(NULL)) == NULL) {
-		fprintf(stderr,"wmnet: doh...can't connect to X server, giving up\n");
-		exit(1);
-	}
+	if ((dpy = XOpenDisplay(NULL)) == NULL)
+		err(1, "doh...can't connect to X server");
 
 	/* assure ourself for a graceful exit */
-	if (atexit(exit_func)) {
-		fprintf(stderr,"wmnet: atexit() failed\n");
-		exit(6);
-	}
+	if (atexit(exit_func))
+		err(6, "atexit() failed");
 
 	signal_action.sa_handler = got_signal;
 	sigemptyset(&signal_action.sa_mask);
@@ -347,40 +351,29 @@ void setup_wmnet(int argc, char **argv) {
 #endif
 	if ((sigaction(SIGCHLD, &signal_action, NULL) == -1) ||
 	    (sigaction(SIGINT, &signal_action, NULL) == -1) ||
-	    (sigaction(SIGTERM, &signal_action, NULL) == -1)) {
-		fprintf(stderr,"wmnet: couldn't set signal handler\n");
-		exit(8);
-	}
-
+	    (sigaction(SIGTERM, &signal_action, NULL) == -1))
+		err(8, "couldn't set signal handler");
 	
 	/* Setup initial foreground color */
 	if(rxcolorString) {
-		if(!XParseColor(dpy, DefaultColormap(dpy, screen), rxcolorString, &thecolor)) {
-			fprintf(stderr, "wmnet: what the heck is %s for a color?\n", rxcolorString);
-			exit(12);
-		}
+		if(!XParseColor(dpy, DefaultColormap(dpy, screen), rxcolorString, &thecolor))
+			err(12, "RX color %s", rxcolorString);
 		shadesOf(&thecolor, rx_pixel);
 	} 
 	if(txcolorString) {
-		if(!XParseColor(dpy, DefaultColormap(dpy, screen), txcolorString, &thecolor)) {
-			fprintf(stderr, "wmnet: what the heck is %s for a color?\n", txcolorString);
-			exit(5);
-		}
+		if(!XParseColor(dpy, DefaultColormap(dpy, screen), txcolorString, &thecolor))
+			err(5, "TX color %s", txcolorString);
 		shadesOf(&thecolor, tx_pixel);
 	}
 	if(labelfgcolorString) {
-		if(!XParseColor(dpy, DefaultColormap(dpy, screen), labelfgcolorString, &thecolor)) {
-			fprintf(stderr, "wmnet: what the heck is %s for a color?\n", labelfgcolorString);
-			exit(24);
-		}
+		if(!XParseColor(dpy, DefaultColormap(dpy, screen), labelfgcolorString, &thecolor))
+			err(24, "foreground label color %s", labelfgcolorString);
 		XAllocColor(dpy, DefaultColormap(dpy, screen), &thecolor);
 		labelfg_pixel = thecolor.pixel;
 	}
 	if(labelbgcolorString) {
-		if(!XParseColor(dpy, DefaultColormap(dpy, screen), labelbgcolorString, &thecolor)) {
-			fprintf(stderr, "wmnet: what the heck is %s for a color?\n", labelbgcolorString);
-			exit(25);
-		}
+		if(!XParseColor(dpy, DefaultColormap(dpy, screen), labelbgcolorString, &thecolor))
+			err(25, "background label color %s", labelbgcolorString);
 		XAllocColor(dpy, DefaultColormap(dpy, screen), &thecolor);
 		labelbg_pixel = thecolor.pixel;
 	}
@@ -393,9 +386,8 @@ void setup_wmnet(int argc, char **argv) {
 	XSetCommand(dpy, main_window, argv, argc);
 
 	/* Get the initial stats for startup */
-	stat_gather();
+	stat_gather(&id);
 	
-
 	/* Rock n Roll */
 	XMapWindow(dpy, main_window);
 
@@ -410,14 +402,11 @@ void setupX(void) {
 	XColor color;
 	XRectangle bound = { 0, 0, 56, 56 }; 
 
-
 	screen = DefaultScreen(dpy);
 
 	delete_atom = XInternAtom(dpy, "WM_DELETE_WINDOW", False);
-	if (delete_atom == None) {
-		fprintf(stderr,"wmnet: I need WindowMaker running! (or at least some window manager)\n");
-		exit(2);
-	}
+	if (delete_atom == None)
+		err(2, "test for window manager");
 	if (XInternAtom(dpy,"_WINDOWMAKER_WM_FUNCTION", True) != None) {
 		if (specified_state == -1) specified_state = WithdrawnState;
 	} else {
@@ -436,10 +425,8 @@ void setupX(void) {
 	grey_pixel = color.pixel;
 
 
-	if ((arrow = XCreateBitmapFromData(dpy, root_window, arrow_bits, arrow_width, arrow_height)) == None) {
-		fprintf(stderr, "wmnet: unable to create arrow bitmap\n");
-		exit(11);
-	}
+	if ((arrow = XCreateBitmapFromData(dpy, root_window, arrow_bits, arrow_width, arrow_height)) == None)
+		err(11, "unable to create arrow bitmap");
 	gcv.graphics_exposures = False;
 	gcv.foreground = tx_pixel[HIGH_INTENSITY]; 
 	gcv.background = darkgrey_pixel;
@@ -468,7 +455,6 @@ void setupX(void) {
 	shints.max_height = 64;
 	shints.flags = PMinSize | PMaxSize;
 	XSetWMNormalHints(dpy, main_window, &shints);
-
 	
 	XStoreName(dpy, main_window, "wmnet");	
 	XShapeCombineRectangles(dpy, *visible_window, ShapeBounding, 4, 4, &bound, 1, ShapeBounding, 0); 
@@ -489,8 +475,6 @@ void createWin(Window *win) {
 	XSetClassHint(dpy, *win, &classHint);
 }
 
-
-
 /* Handles Expose events, repaints the window */
 void redraw(XExposeEvent *ee) {
         static XRectangle cliprect = { 4, 51, 56, 9 };
@@ -498,7 +482,6 @@ void redraw(XExposeEvent *ee) {
 /*	if (wmaker_present == False) XFillRectangle(dpy, *visible_window, graphics_context, 0, 0, 64, 64); */
 	XFillRectangle(dpy, *visible_window, graphics_context, GRAPHBOX_X, GRAPHBOX_Y, GRAPHBOX_WIDTH, GRAPHBOX_HEIGHT); 
 
-
 	XSetForeground(dpy, graphics_context, black_pixel);
 	XFillRectangle(dpy, *visible_window, graphics_context, TOPBOX_X, TOPBOX_Y, TOPBOX_WIDTH, TOPBOX_HEIGHT);
 	XDrawLine(dpy, *visible_window, graphics_context, GRAPHBOX_X_LEFT, GRAPHBOX_Y_TOP, GRAPHBOX_X_LEFT, GRAPHBOX_Y_BOTTOM);
@@ -512,19 +495,16 @@ void redraw(XExposeEvent *ee) {
 		XSetClipMask(dpy, graphics_context, None);
 	}
 
-
 	XSetForeground(dpy, graphics_context, white_pixel);
 	XDrawLine(dpy, *visible_window, graphics_context, GRAPHBOX_X_RIGHT, GRAPHBOX_Y_BOTTOM, GRAPHBOX_X_RIGHT, (GRAPHBOX_Y_TOP + 1)); 
 	XDrawLine(dpy, *visible_window, graphics_context, GRAPHBOX_X_LEFT, GRAPHBOX_Y_BOTTOM, GRAPHBOX_X_RIGHT, GRAPHBOX_Y_BOTTOM);
 
-
 	XSetForeground(dpy, graphics_context, grey_pixel);
 	XSetBackground(dpy, graphics_context, black_pixel);
 	XCopyPlane(dpy, arrow, *visible_window, graphics_context, 7, 0, 7, 9, 53, 5, 1);
 	XCopyPlane(dpy, arrow, *visible_window, graphics_context, 0, 0, 7, 9, 46, 5, 1);
 }
 	
-	
 /* Main loop that is called every delaytime.  This calls stat_gather() and updateSpeedometer() when needed 
  * and takes care of the displaying and scrolling the graph */
 void tock(void) {
@@ -537,18 +517,14 @@ void tock(void) {
 	static unsigned long lifo_out[8] = { 0, 0, 0, 0, 0, 0, 0, 0 };
 	static unsigned int t = 0, blank = 0;
 
-	if (gettimeofday(&timenow, NULL)) {
-		perror("wmnet: gettimeofday()");
-		exit(10);
-	}
+	if (gettimeofday(&timenow, NULL))
+		err(10, "gettimeofday()");
 	since = (timenow.tv_sec * 1000000L + timenow.tv_usec) - (timelast.tv_sec * 1000000L + timelast.tv_usec); 
 	if (since > displayDelay) {
-		lifo_in[t] = diffbytes_in * (1000000L / since);
-		lifo_out[t] = diffbytes_out * (1000000L / since);
+		lifo_in[t] = id.db_in * (1000000L / since);
+		lifo_out[t] = id.db_out * (1000000L / since);
 		t = (t + 1) % 8;
 
-
-
 		/* in */
 		rate_rx = (lifo_in[0] + lifo_in[1] + lifo_in[2] + lifo_in[3] + lifo_in[4] + lifo_in[5] + lifo_in[6] + lifo_in[7]) / (unsigned long)8;
 		if(logscale) percent_rx = (log10(  ((rate_rx * 10000/ maxRate) < 1) ? 1 : ((double)rate_rx / (double)maxRate) * 10000.) / 4.);
@@ -563,52 +539,48 @@ void tock(void) {
 		yy =  GRAPH_Y_UPPER + (GRAPH_HEIGHT * percent_tx) ; 
 		yy = yy > GRAPH_Y_BOTTOM ? GRAPH_Y_BOTTOM : yy; 
 
-
 		/* only update the speedometer every 7th displayDelay */
 		if (t == 7) updateSpeedometer(rate_rx, rate_tx);
 		
 		/* blank var is just for stopping executing the X* funcs when the disp is all black */
-		if ((y == GRAPH_Y_BOTTOM && yy == GRAPH_Y_UPPER) && (diffbytes_in + diffbytes_out) == 0) blank++; else blank = 0;
+		if ((y == GRAPH_Y_BOTTOM && yy == GRAPH_Y_UPPER) && (id.db_in + id.db_out) == 0) blank++; else blank = 0;
 		if (blank < (GRAPH_WIDTH + 1) ) {
 			XCopyArea(dpy, *visible_window, *visible_window, graphics_context, GRAPH_X + 1,
 			   GRAPH_Y, GRAPH_WIDTH - 1, GRAPH_HEIGHT, GRAPH_X, GRAPH_Y);
 			XSetForeground(dpy, graphics_context, darkgrey_pixel);
 			XDrawLine(dpy, *visible_window, graphics_context, GRAPH_X_RIGHT, y, GRAPH_X_RIGHT, yy);
-			if (( (yy == GRAPH_Y_UPPER && diffbytes_out > 0 && rate_rx > rate_tx) || (rate_rx >= rate_tx && yy != GRAPH_Y_UPPER)) ) {
+			if (( (yy == GRAPH_Y_UPPER && id.db_out > 0 && rate_rx > rate_tx) || (rate_rx >= rate_tx && yy != GRAPH_Y_UPPER)) ) {
 				drawColoredLine(GRAPH_Y_UPPER, yy, tx_pixel);				
 			}
-			if ( y != GRAPH_Y_BOTTOM || diffbytes_in > 0) {
+			if ( y != GRAPH_Y_BOTTOM || id.db_in > 0) {
 				drawColoredLine(GRAPH_Y_BOTTOM, y, rx_pixel);
 			}
-			if (( (yy == GRAPH_Y_UPPER && diffbytes_out > 0) || (rate_rx < rate_tx && yy != GRAPH_Y_UPPER)) ) {
+			if (( (yy == GRAPH_Y_UPPER && id.db_out > 0) || (rate_rx < rate_tx && yy != GRAPH_Y_UPPER)) ) {
 				drawColoredLine(GRAPH_Y_UPPER, yy, tx_pixel);				
 			}
 		}
 
-
-		diffbytes_in = diffbytes_out = 0;
+		id.db_in = id.db_out = 0;
 		timelast = timenow;
 	}	
 
-	if (!stat_gather()) {  /* Anything change? */
-		current_rx = rx;
-		current_tx = tx;
+	if (!stat_gather(&id)) {  /* Anything change? */
+		id.current_rx = id.rx;
+		id.current_tx = id.tx;
 		XSetBackground(dpy, graphics_context, black_pixel);
-		if(current_tx == True) {
+		if(id.current_tx == True) {
 			XSetForeground(dpy, graphics_context, tx_pixel[HIGH_INTENSITY]);
 			XCopyPlane(dpy, arrow, *visible_window, graphics_context, 7, 0, 7, 9, 53, 5, 1);
 			/* XFillRectangle(dpy, *visible_window, graphics_context, 55, 5, 4, 4);  */
-		}
-		else {
+		} else {
 			XSetForeground(dpy, graphics_context, grey_pixel);
 			XCopyPlane(dpy, arrow, *visible_window, graphics_context, 7, 0, 7, 9, 53, 5, 1);
 		}
-		if(current_rx == True) {
+		if(id.current_rx == True) {
 			XSetForeground(dpy, graphics_context, rx_pixel[HIGH_INTENSITY]);
 			XCopyPlane(dpy, arrow, *visible_window, graphics_context, 0, 0, 7, 9, 46, 5, 1);
 			/* XFillRectangle(dpy, *visible_window, graphics_context, 55, 12, 4, 4);  */
-		}
-		else {
+		} else {
 			XSetForeground(dpy, graphics_context, grey_pixel);
 			XCopyPlane(dpy, arrow, *visible_window, graphics_context, 0, 0, 7, 9, 46, 5, 1);
 		}
@@ -634,8 +606,6 @@ int updateSpeedometer(int rxRate, int txRate) {
 	} 
 	collectandreturn = True;
 
-
-
 	if (txRate > rxRate) {
 		rate = (txRate + txRate_last) / 2000.;
 		color = tx_pixel[HIGH_INTENSITY];
@@ -644,7 +614,6 @@ int updateSpeedometer(int rxRate, int txRate) {
 		color = rx_pixel[HIGH_INTENSITY];
 	}
 
-
 	if (!clear) {
 		XSetForeground(dpy, graphics_context, black_pixel);
 		XFillRectangle(dpy, *visible_window, graphics_context, 4, 5, 37, 9);
@@ -675,7 +644,6 @@ int updateSpeedometer(int rxRate, int txRate) {
 
 }
 
-
 /* called from within tock to draw the shaded lines making up our bar-graph */
 void drawColoredLine(int y1, int y2, unsigned long *shadecolor) {
 	int subline[4], i;
@@ -709,15 +677,14 @@ void shadesOf(XColor *shade, unsigned long *returnarra
 	XAllocColor(dpy, DefaultColormap(dpy, screen), shade);
 	returnarray[LOW_INTENSITY] = shade->pixel;
 }
-	
 
 /* Here is main, clear at the bottom.  Handles the event loop and calls tock() every delayTime milliseconds */
 int main(int argc, char ** argv) {
 	unsigned int done = False;
 	XEvent event;
-	
+
 	setup_wmnet(argc, argv);
-	
+
 	while(!done) {
 		while(XPending(dpy)) {
 			XNextEvent(dpy, &event);	
@@ -732,9 +699,8 @@ int main(int argc, char ** argv) {
 			case ButtonPress:
 				if(event.xbutton.button == Button1 && click_command != NULL) {
 					if (fork() == 0) {
-						execl("/bin/sh", "sh", "-c", click_command, NULL);
-						perror("wmnet: execl()");
-						exit(15);
+						execl("/bin/sh", "sh", "-c", click_command, (void *)NULL);
+						err(15, "execl(/bin/sh)");
 					}
 				}
 				break;
@@ -747,4 +713,3 @@ int main(int argc, char ** argv) {
 	}
 	return 0;
 }
-
